package com.ruijixiang.leetcode.hot100;

public class leetcode0021 {
    public ListNode mergeTwoLists(ListNode list1,ListNode list2){
        if(list1==null){
            return list2;
        }else if(list2==null){
            return list1;
        }
        ListNode res=new ListNode(0);
        ListNode tmp=res;
        while(list1!=null && list2!=null){
            if(list1.val<list2.val){
                tmp.next=list1;
                list1=list1.next;
            }else{
                tmp.next=list2;
                list2=list2.next;
            }
            tmp=tmp.next;
        }

        if(list1!=null){
            tmp.next=list1;
        }
        if(list2!=null){
            tmp.next=list2;
        }
        return res.next;
    }
}
